Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS6565803 B1
Publication typeGrant
Application numberUS 09/300,325
Publication dateMay 20, 2003
Filing dateApr 27, 1999
Priority dateMay 13, 1998
Fee statusPaid
Also published asCA2372427A1, CN1173891C, CN1359354A, EP1181249A1, WO2001002302A1
Publication number09300325, 300325, US 6565803 B1, US 6565803B1, US-B1-6565803, US6565803 B1, US6565803B1
InventorsJames R. Bolton, R. D. Samuel Stevens, Bertrand Dussert
Original AssigneeCalgon Carbon Corporation
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method for the inactivation of cryptosporidium parvum using ultraviolet light
US 6565803 B1
Abstract
A method for the inactivation of Cryptosporidium oocysts, Giardia cysts and similar organisms comprising irradiating water with ultraviolet light in doses of from about 1 mJ/cm2 to about 175 mJ/cm2.
Images(2)
Previous page
Next page
Claims(14)
What is claimed:
1. A method for the prevention of infection from cryptosporidium oocysts found in drinking water comprising irradiating said water with continuous ultraviolet light having predominant wavelength bands that falls within about 200 nanometers to about 300 nanometers with a dose of from about 1 mJ/cm2 to about 175 mJ/cm2.
2. A method as set forth in claim 1 wherein said dose is from about 3.5 mJ/cm2 to about 175 mJ/cm2.
3. A method as set forth in claim 1 or 2 wherein said ultraviolet light substantially comprises a wavelength of about 254 nanometers.
4. A method as set forth in claim 1 or 2 wherein said ultraviolet light is produced by one of a low pressure mercury lamp or a medium pressure mercury lamp.
5. A method as set forth in claim 4 wherein said ultraviolet light is produced by a low pressure mercury lamp.
6. A method as set forth in claim 4 wherein said ultraviolet light is produced by a medium pressure mercury lamp.
7. A method for the prevention of replication of cryptosporidium oocysts or giardia cysts in drinking water treatment comprising irradiating said water with a continuous source of light having predominant wavelength bands that falls within about 200 nm to about 300 nm and a dose of from about 1 mJ/cm2 to about 175 mJ/cm2.
8. A method as set forth in claim 7 wherein said dose is from about 3.5 mJ/cm2 to about 175 mJ/cm2.
9. A method as set forth in claim 7 or 8 wherein said light substantially comprises a wavelength of about 254 nanometers.
10. A method as set forth in claim 7 or 8 wherein said light is produced by one of a low pressure lamp or a medium pressure lamp.
11. A method as set forth in claim 10 wherein said light is produced by a low pressure lamp.
12. A method as set forth in claim 10 wherein said light is produced by a medium pressure lamp.
13. A method of treating drinking water containing contaminants including cryptosporidium comprising exposing said water to a continuous broad band of ultraviolet radiation with a dose of about 1.0 mJ/cm2 to about 175 mJ/cm2, wherein said exposing step is the sole process for rendering cryptosporidium in said drinking water noninfectious.
14. A method as set forth in claim 13 wherein said dose is from about 3.5 mJ/cm2 to about 175 mJ/cm2.
Description
CROSS-REFERENCE

The present application is a continuation-in-part application of Ser. No. 09/078,116, filed May 13, 1998, entitled METHOD FOR PREVENTING REPLICATION IN CRYPTOSPORIDIUM PARVUM USING ULTRAVIOLET LIGHT, now U.S. Pat. No. 6,129,893.

FIELD OF THE INVENTION

The present invention relates to a method for inactivating Cryptosporidium parvum in water and in particular to a method for the prevention of Cryptosporidium parvum and other protozoans, such as Giardia muris, from establishing infection in human hosts, as measured by the ability to infect neo-natal mice, using low doses of ultraviolet light.

BACKGROUND OF THE INVENTION

It has been generally well recognized that it is necessary to kill or inactivate protozoan oocysts so that they cannot infect susceptible hosts. This is especially important in drinking water. One such method is the use of ultraviolet (“UV”) light. The prior art teaches that a UV dose of at least 3000 mJ/cm2 is required to inactivate Cryptosporidium parvum (Lorenzo-Lorenzo et al., J. Parasitol. 1993, 79, 67-70) and Giardia muris (E. L. Jarol, “Effect of Disinfectants on Giardia Cysts”, CRC Critical Reviews in Environmental Control, 1988, 18, 1-28). Snowball and coworkers (UK Patent Application #9416287.2, Nov. 8, 1984; Wat. Res., 1995, 29, 2583-2586) developed an apparatus that first filtered out Cryptosporidium oocysts and then exposed them to UV doses of 700-800 mJ/cm2. The patent teaches the use of 2 μm screen filters to trap Cryptosporidium oocysts which are then irradiated with a bank of low-pressure Hg lamps for a UV dose of 350-400 mJ/cm2. The filter is then backwashed onto a second filter and the irradiation is repeated for a total dose of 700-800 mJ/cm2. The patent discloses that the treatment “kills” the organisms.

M. J. Lorenzo-Lorenzo, M. E. Area-Mazea, I. Villacorta-Martinez de Maturana and D. Duran-Oreiro [“Effect of Ultraviolet Disinfection of Drinking Water on the Viability of Cryptosporidium parvum Oocysts”, J. Parasitol. 1993, 79(1), 67-70] report the prevention of infection in mice after exposure to at least 150 min. of UV from a (presumably) low-pressure Hg lamp. Although the paper is not clear, it can be inferred that the UV dose applied was over 5000 mJ/cm2 to obtain better than 2 logs reduction in infectivity. The authors claim that exposure to UV for 150 min. or more “eliminates” infectivity, but they give no mechanism other than to say “UV radiation disrupts DNA by causing formation of thy[ia]mine dimers, and high levels may lead to cell death”. At the UV doses they applied, the effects observed almost certainly arose from cell death.

In a paper by A. Bushnell, W. Clark, J. Dunn and K. Salisbury [“Pulsed Light Sterilization of Products Packaged by Blow-Fill-Seal Techniques”, Pharm. Engin. 1997, September/October, 74-83], a pulsed UV technique for “sterilizing” surfaces containing bacteria, fungi, spores, viruses, protozoa and oocysts is described. The required UV doses were reported to be over 1000 mJ/cm2. The effectiveness of the method was assayed using mouse infectivity. At the reported UV doses, the effects were believed to be due to cell death.

In a paper by R. LaFrenz [“High Intensity Pulsed UV for Drinking Water Treatment”, Proc. AWWA WQTC Conference, Denver, Colo., November, 1997], a similar pulsed system was described. While very few details were given, it appears that mouse infectivity assay was used and 6 logs of “inactivation” of Cryptosporidium was obtained at energy levels of approximately 200 mJ/cm2 and greater. The paper claims that the pulsed UV overcomes the “DNA repair mechanism”; however, the UV doses applied are much larger than required with either a steady-state medium pressure or low pressure Hg lamp, as shown herein.

From the references cited above, we infer that the prior art teaches that very large UV doses (>200 mJ/cm2 and up to 5000 mJ/cm2) are required to inactivate Cryptosporidium by “killing” the organisms. Accordingly, it is an object of the invention to provide a method using ultraviolet light to treat water in an effective way so that Cryptosporidium oocysts cannot infect susceptible hosts or, in other words, to “disinfect” the water in regard to Cryptosporidium oocysts that may be present. It is another object of the invention to provide a method using ultraviolet light from a medium-pressure mercury lamp to render the Cryptosporidium oocysts unable to infect. It is yet another object of the present invention to provide a method using ultraviolet light that is cost-effective in treating drinking water to eliminate the potential for infection by Cryptosporidium oocysts and Giardia cysts. The final object of the invention is to provide a method using ultraviolet light from a low-pressure mercury lamp to render Cryptosporidium oocysts and Giardia cysts unable to infect.

SUMMARY OF THE INVENTION

Generally it has been discovered that it is not necessary to “kill” pathogens, such as Cryptosporidium parvum or Giardia muris with ultraviolet light in order to prevent infection; one need only apply enough ultraviolet light to prevent the organism from “replicating”. The method of the present invention prevents replication (cell mitosis) by inactivating the DNA to prevent infection. The UV doses required to prevent replication are orders of magnitude lower than required to “kill” the oocysts. This means that the cost of UV treatment to prevent infection by Cryptosporidium oocysts will be markedly lower.

It has been found that when biological organisms are exposed to ultraviolet light (UV) in the range of 200-300 nm, the UV can be absorbed by DNA, RNA, and proteins. Absorption by proteins can lead to rupture of cell walls and death of the organism. Absorption by DNA or RNA (specifically by thymine bases) is known to cause inactivation of the DNA or RNA double helix strands through the formation of thymine dimers. If enough of these dimers are created in DNA, the DNA replication process is disrupted and hence, in mitosis, the cell cannot replicate. Cells that cannot replicate cannot infect. The present invention utilizes UV doses substantially lower (to achieve the state of hindered replication) by orders of magnitude than those required to cause oocyst death.

The present invention preferably utilizes a broad band (200-300 nm) medium-pressure mercury UV lamp to achieve the disinfection. In another embodiment of the invention, a low-pressure mercury (essentially monochromatic) UV lamp can be used. The dose required with a medium-pressure lamp was measured to be 11 mJ/cm2 to achieve better than 5.9 log disinfection. From this it can be inferred that a dose of 7 mJ/cm2 will achieve better than 4 log disinfection (99.99%) and 3.6 mJ/cm2 will achieve better than 2 log disinfection (99%). For low pressure lamps a dose of 8 and 16 mJ/cm2 was required to achieve 4.1 and 4.3 log disinfection, respectively. Thus, the dose levels of UV are significantly lower than those used before resulting in significantly lower power levels needed to achieve the results. It has been found that inactivation of Cryptosporidium and similar organisms such as Giardia occurs at dosages from about 1 mJ/cm2. Accordingly, the method provides a substantial improvement in the cost effectiveness of UV for the disinfection of contaminated drinking water as regards to Cryptosporidium oocysts and Giardia cysts that may be present. Other advantages will become apparent from a perusal of the following detailed description of a presently preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart that shows the correlation between bench-scale and demonstration-scale tests and the difference between “in vitro” and “in vivo” methods.

FIG. 2 is a chart that shows the correlation between tests using low-pressure versus medium-pressure mercury are UV lamps.

PRESENTLY PREFERRED EMBODIMENT

Experiments were conducted on two different sets of apparatus: a bench-scale collimated beam setup and a demonstration-scale UV reactor.

A well-known bench-scale collimated beam apparatus was used in the test. An upper lamp housing can contain either a 15 W low-pressure Hg lamp (monochromatic at 254 nm) or a 1 kW Rayox medium-pressure Hg lamp (emitting over a broad range from 200-300 nm). Each lamp has its own power supply in the lower housing. A black plastic collimator (48 cm long and 6.4 cm diameter) extends vertically down from the lamp housing with a pneumatically-driven shutter in between. The cell suspension (in finished water from the Mannheim Water Treatment Plant, Kitchener, Ontario, Canada) to be irradiated is placed in a Petri dish (with a stir bar) on top of a stirring motor below the collimator and exposed for a fixed length of time to achieve the desired UV dose. The UV irradiance is measured with an Interational Light Model 1400 Radiometer with a Model SED240 detector. Proper account is taken of the variation of the detector sensitivity with wavelength, the attenuation of irradiance in the water and of the irradiance distribution over the top of the Petri dish. The UV dose (mJ/cm2) is the average UV irradiance (mW/cm2) in the water times the exposure time (s).

Demonstration-scale challenges of Cryptosporidium parvum and Giardia muris were carried out on filtered water at the Mannheim Water Treatment Plant in Kitchener, Ontario, Canada with a 111 L (29.4 gal) UV reactor containing 6×1 kW Rayox Sentinel™ medium-pressure UV lamps mounted horizontally across a tower type UV reactor. The organisms were introduced upstream of a static mixer ahead of the reactor and collected on 1 micron filters after the reactor. The overall flow rate during each test was about 215 gpm (814 L/min). The filters were shipped to St. Albans, Vt. where the organisms were extracted from the filters and concentrated. All organisms were subjected to in vitro assays (fluorogenic vital dyes and excystation); four of the Cryptosporidium samples were shipped to the Department/Laboratory of the University of Arizona for mouse infectivity assays.

The UV-treated oocysts were enumerated with a hemocytometer, using bright-field microscopy to determine the concentration of oocysts present in each tube. These preliminary counts were used to calculate the dilutions that were necessary for preparation of oocyst inocula for neonatal mice.

Upon arrival of the oocysts at the University of Arizona, the infectivity of the oocysts was determined by their inoculation into 4 to 6-day-old CD-1 outbred mice. The mice were challenged with oocyst inocula prepared in sterile water adjusted to pH 7. All inocula were prepared by serial dilution from a pre-enumerated oocyst suspension. A calibrated pipette was used for all dilutions and following dilution, oocysts inocula were re-enumerated before they were fed to the mice. The counts were performed and cross-checked by two technicians. The oocysts were administered orally in 10 μL inocula with a dedicated, calibrated pipette equipped with a standard tip. The inocula were administered slowly with the mouse held gently in the palm of the technician's hand until the entire inoculum was swallowed. The animals were sacrificed seven days post-inoculation and approximately 2 cm of terminal ileum was excised. The tissue samples were fixed in formalin, embedded in paraffin, sectioned, mounted on microscope slides, stained, and examined for the presence of endogenous stages of C. parvum in the brush-borders of the intestinal villi. Specimens with parasites were scored positive and those without parasites were scored negative.

The UV dose (mJ/cm2) applied in the reactor was calculated from the average irradiance (mW/cm2) (determined from a sophisticated point source summation model of the reactor) times the residence time in the reactor (about 8.3 s). The UV dose was varied by turning one or two lamps on at “low” or “full” power.

A subsequent set of bench-scale experiments was conducted to assess differences between low-and medium-pressure Hg lamps. The conditions for these experiments were essentially the same as that for the bench-scale experiments described above except that one set of experiments was conducted using the low-pressure Hg lamp and one set with the medium-pressure Hg lamp.

SUMMARY OF THE RESULTS

Assays

Two in vitro assays (fluorogenic vital dyes and maximized excystation) and one in vivo assay (neonatal mouse infectivity) were used to assess the viability and infectivity of the Cryptosporidium parvum oocysts for both the bench- and demonstration-scale experiments. In addition, one in vitro assay (maximized excystation) was performed in the demonstration scale experiments for Giardia muris cysts. Also in vivo testing for Giardia was performed.

Bench-Scale Study

Viability and Infectivity of Untreated and Process Control Oocysts of Cryptosporidium

The initial viability assessment in the trip control (untreated oocyst suspensions) indicated high viability with the fluorogenic vital dyes (91%±2%) and maximized in vitro excystation (76%±4%. These results were corroborated with mouse infectivity, which indicated that 75 oocysts were necessary for 56% infection in CD-1 neonatal mice. In the process control (oocysts subjected to all experimental procedures without exposure to UV light), the fluorogenic vital dyes indicated a viability of 85±3% and maximized in vitro excystation a viability of 86%. For the process controls, an inoculum of 50 oocysts caused approximately 80% infection in neonatal mice. These data were used to “normalize” the experimental viabilities for the in vitro assays by multiplying by (1/0.85=1.18) in the case of fluorogenic vital dyes and by (1/0.86=1.16) in the case of maximized excystation.

Viability and Infectivity of UV-exposed Oocysts

Four UV doses were examined to assess their effect on oocyst viability and infectivity. The normalized in vitro viability data for the UV-exposed oocysts are given in Table 1a. The log viability factor is the logarithm of the ratio of the viability percentage relative to that of the process control.

The in vivo neonatal mouse infectivity data are given in Table 1b and were ascertained from microscopic examination of tissue sections derived from the ileum of individual mice, seven days past infection. The percentage infectivity for a given dose was determined from the ratio of infected mice to the total number of mice receiving that dose. In order to establish a log viability for infection, the percentage infectivity values were extrapolated from a log it dose response model, which was generated from previous infectivity studies and has the following equation.

response log it=−7.536+3.867 log10 Dose=ln[P/(1−P)]

where P is the proportion of mice infected. The response log it is very similar to that described by Finch et al. [Finch, G. R., Daniels, C. W., Black, E. K., Schaefer III, F. W. and Belosovic, M. 1993. “Dose Response of Cryptosporidium parvum in Outbred Neonatal CD-1 Mice”. Applied and Environmental Microbiology. 59(11):3661-3665.] and is used to determine the number of infectious oocysts in a given oocyst inoculum.

For example, oocyst exposure to 123 mJ/cm2 of medium-pressure UV caused infection in 1 of 25 mice at an inoculum of 1.0×105 oocysts. Substitution of these data into the log it response equation indicates

Response log it=ln[0.04/0.96]=−3.178

Substituting:

−3.178=−7.536+3.867 log10 Dose

log10 (no. of infectious oocysts)=(7.536−3.178)/3.867=1.127

No. of infectious oocysts=13

This calculation indicates that following treatment of oocysts with UV and administration of an inoculum of 1.0×105 oocysts, approximately 13 oocysts were capable of causing infection in mice.

The log viability for infection was calculated by the following equation:

 log viability (for infection)=log10[(no. of infectious oocysts)/(original inoculum)]

In the example,

log viability (for infection)=log10[13/100,000]=−3.9

These infectivity data in Table 1b indicate that the in vitro assays greatly underestimate oocyst inactivation when compared to in vivo mouse infectivity.

TABLE 1a
Normalized Viability Factors (percent)
for in vitro Bench-Scale Tests
Viability Percentage* Log Viability
UV Dose (mJ/cm2) Vital Dyes Excystation Vital Dyes Excystation
41 100 98 0.00 −0.01
82 98 99 −0.01 0.00
123 78 98 −0.11 −0.01
246 4.4 1.3 −1.36 −1.89
*Values over 100% are considered to be 100%

TABLE 1b
Percentage Neo-natal Mouse Infectivity for in vitro Bench-Scale Tests
Percentage infectivity and Inoculum (bold numbers)
UV Dose (mJ/cm2) Inoculum 1 Inoculum 2 Inoculum 3 Log Viability
0 (Trip Control) 35% (8/23)  56% (14/25)  79% (19/24)
25  75  150
0 (Process 82% (22/27) 100% (24/24) 100% (27/27)
Control) 50 500 5000 0.00
 41  0% (0/28)  0% (0/26)  0% (0/24)
1,000 10,000 100,000 <−4.5
 82  0% (0/27)  0% (0/26)  0% (0/24)
1,000 10,000 100,000 <−4.5
123  0% (0/25)  0% (0/23)  4% (1/25)
1,000 10,000 100,000 −3.9
246  0% (0/24)  0% (0/27)  0% (0/27)
1,000 10,000 100,000 <−4.5

Demonstration Scale Study

Viability and Infectivity of Untreated and Process Control Cryptosporidium Oocysts and Giardia Cysts

The initial viability assessment in the trip control (untreated Cryptosporidium oocyst suspensions) indicated high viability with the fluorogenic vital dyes (82%±4%) and maximized in vitro excystation (81%±8%). These results were corroborated with mouse infectivity, which indicated that 75 oocysts were necessary for 35% infection in CD-1 neonatal mice. In two process controls (oocysts subjected to all experimental procedures without exposure to UV light), the fluorogenic vital dyes indicated an average viability of 77±5%, while maximized in vitro excystation indicated an average viability of 38%±8% for Cryptosporidium and 53%±23% for Giardia. For the process controls, an inoculum of 50 oocysts caused approximately 44% infection in neonatal mice. These data were used to “normalize” the experimental viabilities for the in vitro assays by multiplying by (1/0.72=1.39) in the case of fluorogenic vital dyes and by (1/0.38=2.63) in the case of maximized excystation for Cryptosporidium oocysts and (1/0.53=1.89) for Giardia.

Viability and Infectivity of UV-exposed Oocysts

In the demonstration-scale disinfection experiments, five UV doses were examined to assess their effects on Cryptosporidium parvum viability with three doses used to asses infectivity. Only in vitro excystation was used to assess the viability of Giardia muris cysts.

The normalized in vitro viability data for the UV-exposed oocysts and cysts are given in Table 2a and the in vivo neonatal mouse infectivity data are given in Table 2b. These data again indicate that the in vitro assays greatly underestimate oocyst inactivation when compared to in vivo mouse infectivity.

TABLE 2a
Normalized Viability Factors (percent) for
in vitro Demonstration-Scale Tests
Viability Percentage* Log Viability
Cryptosporidium Giardia Cryptosporidium Giardia
UV Dose Vital Excy- Excy- Vital Excy- Excy-
(mJ/cm2) Dyes station station Dyes station station
19 100 100 100 0.00 0.00 0.00
66 100 82 100 0.00 −0.09 0.00
131 35 90 69 −0.46 −0.05 −0.16
151 12 32 43 −0.92 −0.50 −0.37
159 6.8 36 38 −1.17 −0.44 −0.42
*Values over 100% are considered to be 100%

TABLE 2b
Percentage Neo-natal Mouse Infectivity for in vitro
Demonstration-Scale Tests for Cryptosporidium
Percentage infectivity
and Inoculum (bold numbers)
UV Dose (mJ/cm2) Inoculum 1 Inoculum 2 Inoculum 3 Log Viability
0 (Trip Control)  5% (2/38)  35% (14/40)  65% (15/23)
25  75 150
0 (Process 44% (11/25) 100% (20/20) 100% (23/23)
Control) 50 500 5000 0.00
 19  0% (0/18)  0% (0/18)  4.5% (1/22)
1,000 10,000 100,000 −3.9
 66  0% (0/22)  0% (0/26)  0% (0/25)
1,000 10,000 100,000 <−4.5
159  0% (0/24)  0% (042)  0% (0/24)
1,000 10,000 100,000 <−4.5

Comparison of Bench-and Demonstration-Scale Disinfection Studies to Assess Oocyst Inactivation

The oocyst inactivation data are illustrated in FIG. 1 as log(viability ratio versus UV). The viability ratio is defined as the ratio of the viability of the UV-treated oocysts to that of the process control versus UV dose. The dramatic difference between the in vitro (fluorogenic vital dyes and excystation) and in vivo (neonatal mouse infectivity) assays may be explained in the context that the in vitro assays measure integrity/permeability of the oocyst wall, not the ability of the oocyst to infect its host; whereas the in vivo assay measures the ability of the oocysts to infect a susceptible host.

Validation of the UV Dose for the Demonstration-scale Study

The UV dose for the demonstration-scale study depends on the average irradiance calculated from a complex mathematical model. It is thus important to have an independent assessment of the accuracy of the calculation. An examination of FIG. 1 shows an excellent agreement between the bench-scale and demonstration-scale studies especially considering the uncertainties associated with these assays. Thus the UV dose calculated in the demonstration-scale studies can be considered validated by the excellent agreement with the experimentally obtained data from the collimated beam tests.

Bench-Scale Study Comparing Effects of Low- and Medium-Pressure Hg Lamps

The effects of three low-pressure UV doses (8, 16 and 33 mJ/cm2) and two medium-pressure UV doses (11 and 20 mJ/cm2) on the viability and infectivity of Cryptosporidium parvum oocysts (suspended in Mannheim finished water) were examined.

Viability and Infectivity of Untreated and Process Control Oocysts of Cryptosporidium

The initial viability assessment in untreated oocyst suspensions indicated a viability of 80%±4% with the fluorogenic vital dyes and 71%±6% by maximized in vitro excystation. In the process control (oocysts subjected to all experimental procedures without exposure to UV light), the fluorogenic vital dyes indicated a viability of 68±4% and maximized in vitro excystation a viability of 67%. For the process controls, an inoculum of 50 oocysts caused approximately 53% infection in neonatal mice. These data were used to “normalize” the experimental viabilities for the in vitro assays by multiplying by (1/0.68=1.47) in the case of fluorogenic vital dyes and by (1/0.67=1.49) in the case of maximized excystation.

Viability and Infectivity of UV-exposed Oocysts

The normalized in vitro viability data for the UV-exposed oocysts are given in Table 3a and the in vivo neonatal mouse infectivity data are given in Table 3b. These data again indicate that the in vitro assays greatly underestimate oocyst inactivation when compared to in vivo mouse infectivity. Also, there is a definite difference between the data for the low-pressure Hg lamp and that for the medium-pressure Hg lamp. None of the mice became infected in any of the medium-pressure experiments, whereas there were definite indications of infectivity for at least the two lowest low-pressure UV doses. To achieve 5.9 logs inactivation, it is preferable to administer at least between 11 and 22 mJ/cm2 with a low-pressure Hg lamp. Typically, 11 mJ/cm2 suffices for the medium-pressure Hg lamp. However, it has been found that there is little difference in UV sensitivity between the medium-pressure and low-pressure Hg lamps.

TABLE 3a
Normalized Viability Factors (percent) for in vitro
Bench-Scale Tests Comparing Low-Pressure (LP)
versus Medium-Pressure (MP) Hg Lamps
UV Dose Viability Percentage* Log Viability
(mJ/cm2) Vital Dyes Excystation Vital Dyes Excystation
LP-8 94 78 −0.03 −0.11
LP-16 100 88 0.00 −0.06
LP-33 91 91 −0.04 −0.04
MP-11 100 61 0.00 −0.22
MP-20 100 72 0.00 −0.14
*Values over 100% are considered to be 100%

TABLE 3b
Percentage Neo-natal Mouse Infectivity for in vitro Bench-Scale Tests
Comparing Low-Pressure (LP) versus Medium-Pressure (MP) Hg Lamps
Percentage infectivity and Inoculum (bold numbers)
UV Dose (mJ/cm2) Inoculum 1 Inoculum 2 Inoculum 3 Log Viability
0 (Process Control) 53% (10/19) 79% (19/24) 100% (6/6)
50 100 1000 0.00
LP-8  0% (0/17)  5% (1/19)  42% (8/19)
10 4 10 5 10 6 −4.1
LP-16  0% (0/27)  0% (0/20)  26% (5/19)
10 4 10 5 10 6 −4.3
LP-33  0% (0/21)  4% (1/23)  0% (0/24)
10 4 10 5 10 6 <−5.9
MP-11  0% (0/20)  0% (0/25)  0% (0/19)
10 4 10 5 10 6 <−5.9
MP-20  0% (0/23)  0% (0/22)  0% (0/24)
10 4 10 5 10 6 <−5.9

TABLE 4
Preliminary Results of the Dosage Relationship
of Cryptosporidium and Gardia.
UV Dose (mJ/cm2) Cryptosporidium Giardia
0 0
3.4 2.0
4.8 2.0
8 3.5
16 3.0
34 3.5
0 0
5 2.3
10 2.6
21 2.9
83 2.8

While presently referenced embodiments of the invention have been described, the invention may be otherwise embodied within the scope of the appended claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2072416Jan 16, 1933Mar 2, 1937R U V Engineering CorpMethod of irradiating substances with active rays
US2072417Jan 19, 1934Mar 2, 1937R U V Engineering CorpMethod of irradiating substances with active rays
US2438168Sep 25, 1944Mar 23, 1948Hearst Gabrielle MStabilization of shell eggs
US2482507Jun 28, 1944Sep 20, 1949Westinghouse Electric CorpMethod of destroying microorganisms
US2930706Feb 27, 1959Mar 29, 1960Inst Divi Thomae FoundationPreparation and packing of citrus fruit products
US3462597Jul 29, 1966Aug 19, 1969Ultra Dynamics CorpUltraviolet fluid purifier having manually operable wiper means
US3814680May 6, 1971Jun 4, 1974Meltzer HProcess and apparatus for purification of materials
US3817703Sep 9, 1971Jun 18, 1974Filtering Materials IncLaser energized sterilization method and apparatus
US3941670Nov 12, 1970Mar 2, 1976Massachusetts Institute Of TechnologyMethod of altering biological and chemical activity of molecular species
US3948772Apr 16, 1975Apr 6, 1976Sidney EllnerSplit stream ultraviolet purification device
US3955921Oct 15, 1974May 11, 1976Eli Lilly And CompanyMethod of killing microorganisms in the inside of a container utilizing a laser beam induced plasma
US4042325Jun 21, 1976Aug 16, 1977Eli Lilly And CompanyMethod of killing microorganisms in the inside of a container utilizing a plasma initiated by a focused laser beam and sustained by an electromagnetic field
US4112124Apr 26, 1971Sep 5, 1978Drisan Packaging Ltd.Food packaging system and method
US4141686Mar 24, 1977Feb 27, 1979Lewis James HDisposable liquid sterilizer unit
US4179616Oct 2, 1978Dec 18, 1979Thetford CorporationApparatus for sanitizing liquids with ultra-violet radiation and ozone
US4229202Jan 29, 1979Oct 21, 1980Great Circle AssociatesWastewater treatment with ultraviolet disinfection and increased capacity
US4230571Jan 22, 1979Oct 28, 1980Dadd Robert COzone/ultraviolet water purification
US4265747May 22, 1979May 5, 1981Sterling Drug Inc.Disinfection and purification of fluids using focused laser radiation
US4296066Jan 28, 1980Oct 20, 1981Schenck GuentherMultichamber photoreactor
US4304996Apr 9, 1980Dec 8, 1981Pure Cycle CorporationWater sterilizer and organic matter measurement instrument
US4372860Feb 24, 1981Feb 8, 1983H. & P. Kaas System Teknik ApsMethod and an apparatus for cleaning water in a swimming pool
US4390432Aug 6, 1981Jun 28, 1983Marui Industry Co., Ltd.Method of purifying water in fish keeping water tank
US4433244Mar 19, 1982Feb 21, 1984Baxter Travenol Laboratories, Inc.Apparatus for irradiating tubing connections
US4464336Nov 29, 1982Aug 7, 1984Ushio Denki KabushikikaishaMethod of sterilization
US4479762Dec 28, 1982Oct 30, 1984Baxter Travenol Laboratories, Inc.Prepackaged fluid processing module having pump and valve elements operable in response to applied pressures
US4534282May 4, 1982Aug 13, 1985Marinoza Rene AProcess and apparatus for treating food products
US4535247Jul 11, 1983Aug 13, 1985Kurtz Mark EWater sterilization system
US4601822Feb 17, 1982Jul 22, 1986Frank ZamburroWater purifying apparatus
US4623467Jun 25, 1984Nov 18, 1986International Manufacturing And Water Vending CompanyWater purifying and vending apparatus
US4661264Mar 31, 1986Apr 28, 1987Autotrol CorporationLaser disinfection of liquids
US4766321May 13, 1987Aug 23, 1988Jung G. LewSymbiotic filter-sterilizer
US4769131Oct 3, 1986Sep 6, 1988Pure Water TechnologiesUltraviolet radiation purification system
US4816145Dec 30, 1985Mar 28, 1989Autotrol CorporationLaser disinfection of fluids
US4871559Apr 28, 1988Oct 3, 1989Maxwell Laboratories, Inc.Methods for preservation of foodstuffs
US4902411Oct 24, 1988Feb 20, 1990Lin Frank W GDrinking water purifier
US4904874Aug 2, 1988Feb 27, 1990Ultraviolet Purification SystemsApparatus for irradiating fluids
US4910942Aug 11, 1989Mar 27, 1990Maxwell Laboratories, Inc.Methods for aseptic packaging of medical devices
US4952511Apr 14, 1989Aug 28, 1990Martek CorporationPhotobioreactor
US4968891Nov 22, 1989Nov 6, 1990Jhawar Makhan MDisinfecting a fluid with ultraviolet radiation
US4971687Apr 24, 1989Nov 20, 1990John B. Knight, Jr.Apparatus for water treatment
US5034235Jun 8, 1989Jul 23, 1991Maxwell Laboratories, Inc.Methods for presevation of foodstuffs
US5037618Apr 13, 1990Aug 6, 1991Peroxidation Systems, Inc.Oxidation chamber
US5118422Jul 24, 1990Jun 2, 1992Photo-Catalytics, Inc.Photocatalytic treatment of water
US5120450Dec 27, 1989Jun 9, 1992Stanley Jr E GlynnUltraviolet radiation/oxidant fluid decontamination apparatus
US5124131Dec 10, 1990Jun 23, 1992Ultraviolet Energy Generators, Inc.Compact high-throughput ultraviolet processing chamber
US5141636Jan 8, 1991Aug 25, 1992United States Of America As Represented By The Administrator, National Aeronautics And Space AdministrationPurification system
US5144146Apr 11, 1991Sep 1, 1992Ultraviolet Energy Generators, Inc.Method for destruction of toxic substances with ultraviolet radiation
US5151252Oct 17, 1991Sep 29, 1992Purus, Inc.Chamber design and lamp configuration for an ultraviolet photochemical reactor
US5207921Apr 1, 1992May 4, 1993Vincent John DIndustrial waste water reclamation process
US5208461Oct 3, 1991May 4, 1993Simon Hydro-Aerobics, Inc.Ultra-violet wastewater disinfection system
US5234606Oct 9, 1991Aug 10, 1993Nec Environment Engineering Ltd.Method and system for recovering wastewater
US5235905Jun 5, 1992Aug 17, 1993Foodco CorporationHigh pulsed voltage systems for extending the shelf life of pumpable food products
US5256299Jul 2, 1990Oct 26, 1993International Environmental Systems, Inc., UsaMethod and apparatus for liquid treatment
US5364645Oct 30, 1992Nov 15, 1994The Regents Of The University Of CaliforniaMethod of controlling microorganisms by pulsed ultraviolet laser radiation
US5389254Aug 13, 1993Feb 14, 1995Olin CorporationWater treatment system
US5433866Mar 18, 1994Jul 18, 1995Hoppe; Jeffrey E.System and method for treating water
US5441179May 18, 1994Aug 15, 1995Marsh; Stephen A.Ultra-violet disinfecting device adapted for use with bottled water dispenser
US5443733May 21, 1993Aug 22, 1995Daimler-Benz Aerospace Airbus GmbhMethod and apparatus for treating waste water
US5446289Apr 15, 1994Aug 29, 1995Despatch Industries Limited PartnershipUltraviolet passthrough sterilization device
US5451791Feb 8, 1995Sep 19, 1995Mark; Farvell M.Water disinfecting apparatus
US5466425Jul 8, 1994Nov 14, 1995Amphion International, LimitedBiological decontamination system
US5494576Apr 27, 1995Feb 27, 1996Pollution Management IndustriesSystem and method for treating water
US5498394Oct 16, 1992Mar 12, 1996Molecucare, Inc.Apparatus and method for a bio-conditioning germicidal dryer
US5543056Jun 29, 1994Aug 6, 1996Massachusetts Institute Of TechnologyMethod of drinking water treatment with natural cationic polymers
US5545335Sep 26, 1994Aug 13, 1996Adrian P. SweenWater purifier
US5582741Sep 6, 1994Dec 10, 1996Nec Environment Engineering Ltd.Method for treating polluted water
US5591434Apr 15, 1994Jan 7, 1997Kansas State University Research FoundationDNA sequence encoding surface protein of cryptosporidium parvum
US5639452Sep 15, 1993Jun 17, 1997Messier; Pierre JeanIodine/resin disinfectant and a procedure for the preparation thereof
US5675153 *Oct 6, 1994Oct 7, 1997Snowball; Malcolm RobertUV apparatus for fluid treatment
US5780860 *Aug 6, 1996Jul 14, 1998The Regents Of The University Of CaliforniaUV water disinfector
US5785845Nov 9, 1995Jul 28, 1998Colaiano; RobertWater purifying system
US5786812Jun 11, 1996Jul 28, 1998Smk CorporationTablet pointer
US5900211Oct 31, 1996May 4, 1999Purepulse TechnologiesDeactivation of organisms using high-intensity pulsed polychromatic light
US5935431Jan 15, 1997Aug 10, 1999Korin; AmosUltraviolet ozone water purifier for water disinfection
US5942110Dec 29, 1997Aug 24, 1999Norris; Samuel CWater treatment apparatus
DE1946267A1Sep 12, 1969Mar 18, 1971Heinz DoevenspeckDisperse phases from disperse systems
DE2907887A1Mar 1, 1979Sep 11, 1980Heinz DoevenspeckVerfahren zur gewinnung einzelner phasen aus dispersen systemen
EP0003879A1Feb 9, 1979Sep 5, 1979Thetford CorporationApparatus for sanitising liquids
EP0005235A2Apr 25, 1979Nov 14, 1979Ihle Ingenieurgesellschaft mbHApparatus for disinfecting water and/or removing algae from it
EP0027278A1Oct 16, 1980Apr 22, 1981Günther Otto Prof. Dr. SchenckCombined iodine-ultraviolet water desinfection process
EP0270879A1Nov 14, 1987Jun 15, 1988Otto JoklikMethod and apparatus for disinfecting aqueous mediums, especially drinking water
EP0316687A1Nov 4, 1988May 24, 1989Knight, John B., Jr.Water treatment apparatus
EP0317735A2Sep 27, 1988May 31, 1989Katadyn Produkte AGApparatus for disinfecting waste water
EP0343998A1May 25, 1989Nov 29, 1989John M. Fuller LtdWater treatment systems
EP0634362A1Jul 15, 1994Jan 18, 1995Akitoshi SugimotoLiquid purification system
EP0643016A1Sep 15, 1994Mar 15, 1995Hans MüllerDevice for disinfection and sterilization of water with UV light
EP0671363A2Sep 8, 1994Sep 13, 1995Nec Environment Engineering, Ltd.Method and system for treating polluted water
EP0686601A1May 5, 1995Dec 13, 1995Stoutz Jean DeProcess and device for treating liquids with UV radiation
EP0721920A1Jan 12, 1996Jul 17, 1996OTV Omnium de Traitements et de Valorisation S.A.UV irradiation reactor for the treatment of liquids
EP0806398A2Apr 28, 1997Nov 12, 1997EISENWERKE FRIED. WILH. DÜKER GmbH &amp; Co.Installation for disinfection of fluids such as water
EP0968962A1Jun 23, 1997Jan 5, 2000Kamurov, Alexandr SemenovichMethod and device for uv treatment of liquid, air and surface
GB364128A Title not available
GB902760A Title not available
GB1052513A Title not available
GB1346521A Title not available
GB1448411A Title not available
GB1548997A Title not available
GB1581998A Title not available
GB2292097A Title not available
NL7502834A Title not available
Non-Patent Citations
Reference
1"Evaluation of the Safe Water Solutions LLC Cryptosporidium Inactivation Device for Inactivation of Cryptosporidium Parvum Oocysts," Mar. 1996.
2"Inactivation of Oocysts of Cryptosporidium Parvum by Ultraviolet Irradiation" Wat. Res., vol. 29, No. 11, pp. 2583-2586 (1995) Authors: A.T. Campbell, L.J. Robertson, M.R. Snowball and H.V. Smith.
3"Ultraviolet Light Disinfection Technology in Drinking Water Application-An Overview,", US Environmental Protection Agency, Sep. 1996, EPA 811-R-96-002.
4"Ultraviolet Sterilization" Handbook of Water Purification, second edition, Ellis Horwood Series in Water and Wastewater Technology, author: Gunther O. Schenk.
5"Ultraviolet Light Disinfection Technology in Drinking Water Application—An Overview,", US Environmental Protection Agency, Sep. 1996, EPA 811-R-96-002.
6A. Bushnell, W. Clark, J. Dunn and K. Salisbury, "Pulsed Light Sterilization of Products Packaged by Blow-Fill-Seal Techniques," Pharm. Ngin. 1997, Set/Oct. 74-83.
7A.T. Campbell, L.J. Robertson, M.R. Snowball and H.V. Smith, "Inactivation of Oocysts of Cryptosporidium parvum by Ultraviolet Irradiation" Wat. Res., vol. 29, No. 11, pp. 2583-2586 (1995).
8Abbaszadegan M. et al, "The Disinfection Efficacy of a Point-of-Use Water Treatment System Against Bacterial, Viral and Protozoan Waterborne Pathogens" Water Research, NL, Elsevier Science Publishers, Amsterdam, vol. 31, No. 3, Mar. 1, 1997 (Mar. 1, 1997), pp. 574-582.
9Abstract: Baron, J., "Repair of Wastewater Microorganisms After Ultraviolet Disinfection Under Seminatural Conditions," Journal-Water Environ. Res., vol. 69, No. 5, pp. 992-998, 1997 (NDN-057-0005-2321-9), prior art.
10Abstract: Boisdon, V., "Water Disinfection Efficiency by Chemical Processes and UV Radiation," Journal-Tech. Sci. Methods, Genie-Urbain-Genie Rural, No. 3, pp. 228-236, 1995 (NDN-057-0002-4401-0).
11Abstract: Diaz, M.E.; Law, S.E., "Ultraviolet Photon Enhanced Ozonation for Microbiological Safety in Poultry Processing Water," Book Monograph, PAP ASAE, vol. 3, 13 pp., Meeting Reports, 1997 (NDN-122-0185-1573-2).
12Abstract: Grigor'eva, L. V.; Korchak, G.I.; Bei, T. V., "Stability and Reactivation in Water of Adhesiveness and Coliciogenicity of Enterobacteria Under Action of Ultraviolet Radiation," Journal-Khim Tekhnol Vody, Vo. 14, No. 10, pp. 794-799, 1992 (NDN-122-0117-8831-7).
13Abstract: Ho. K.W.A., "Application of Ultraviolet Disinfection in a Tertiary Wastewater Treatment Plant," Book Monograph, 53 pp., 1982 (NDN-122-0010-8803-7).
14Abstract: Hoyer, O, "Testing Performance and Monitoring of UV Systems for Drinking Water Disinfection," Journal-Water Supply, vol. 16, No. 1-2, pp. 424-429, 1998 (NDN-057-0007-0250-3).
15Abstract: Huber, S.; Popp, W., "Experiences with UV Irradiation of Purified Water for the Purpose of Germ Reduction," Meeting Paper, Biological Abstracts/RRM vol. 046, Iss. 006, Ref. 082899, German, pp. 290-305, (NDN-007-0440-6348-2), prior art.
16Abstract: Job, G.D.; Trengove, R.; Realey, G.J., "Trials Using a Mobile Ultraviolet Disinfection System in South West Water," Journal-J. Inst. Water Environ. Manage., vol. 9, No. 3, pp. 257-263, 1995 (NDN-057-0003-2747-9).
17Abstract: Jolis, D.; Hirano, R.; Pitt, P., "Teritiary Treatment Using Microfiltration and UV Disinfection for Water Reclamation," vol. 71, No. 2, pp. 224-231, 1999.
18Abstract: Kolman, R., "Use of UV Radiation for Disinfecting Water in First Stage Growth Tanks Stocked with Rainbow Trout (Oncorhynchus Mykiss) Larvae," Journal-Rocz. Nauk Noln. Ser. H Rybactwo, vol. 102, No. 1, pp. 71-86, 1989 (NDN-122-0118-6891-1).
19Abstract: Laine, S.; Poujol, T.; Dufay, S.; Baron, J.; Robert, P., "Treatment of Stormwater to Bathing Water Quality by Dissolved Air Flotation, Filtration and Ultraviolet Disinfection," Journal-Water Science & Technology, Vo.. 38, No. 10, pp. 99-105, 1998 (NDN-057-0007-7627-4), prior art.
20Abstract: Loge, F.J.; Darby, J.L.; Tchobanoglous, G., "UV Disinfection of Wastewater: Probabilistic Approach to Design", Journal-J. Environ. Eng., vol. 122, No. 12, pp. 1078-1084, 1996 (NDN-057-0004-1702-0).
21Abstract: Martinez, D., Farre, J., Borrull, F., Calull, M., Ruana, J., Colom, A., "Capillary Zone Electrophoresis With Indirect UV Detection of Haloacetic Acids in Water" Journal of Chromatography A, vol. 808, No. 1-2, 1998, pp. 229-236, Research Article, (NDN-007-0673-7062-0).
22Abstract: Miyamoto, M; Yamaguchi, Y.; Sasatsu, M., "Disinfectant Effects of Hot Water, Ultraviolet Light, Silver Ions and Chlorine on Strains of Legionella and Nontuberculous Mycobacteria," Journal-Microbios, vol. 101, No. 398, pp. 7-13 (NDN-122-0207-2336-1), prior art.
23Abstract: Moreland, Rijal, G; Fujioka, R. V., "Evaluation of a UV System to Disinfect Wastewater From a 3 MGD Plant Based on Inactivation of Six Microbial Indicators", Journal-Abstracts o the General Meeting of the American Society for Microbiology, vol. 96, 1996, pp. 397, ISSN 1060-2011, Meeting Abstract, 96th General Meeting of the American Society for Microbiology, May 19-23, 1996, New Orleans, Louisiana (NDN-007-0552-6836-9).
24Abstract: Oppenheimer, J.A.; Jacangelo, J.G.; Laine, J.M.; Hoagland, J.E., "Testing the Equivalency of Ultraviolet Light and Chlorine for Disinfection of Wastewater to Reclamation Standards," Journal-Water Environ. Res., vol. 69, No. 1, pp. 14-24, 1997 (NDN-057-0004-7387-3).
25Abstract: Pires, M.R., Pisani, B., Prandi, M.A.G., Simoes, M., "Desinfection of Water with Ultraviolet Radiation: Bactericide Efficiency" Journal-Revista do Instituto Adolfo Lutz, vol. 57, No. 1, 1998, pp. 29-34, Research Article, (NDN-0677-2758-3).
26Abstract: Tomowich, D., "UV Disinfection for Wastewater Reuse," Journal-World Water and Environmental Engineering Y World Water Environm. Eng., vol. 21, No. 12, pp. 22-23, 1998 (NDN-057-0008-2462-1), prior art.
27Abu-Ghararah, Z.H., "Effect of Temperature on the Kinetics of Wastewater Disinfection Using Ultraviolet Radiation," Journal-J. Environ. Sci. Health, Part A, vol. A29, No. 3, pp. 585-603, 1994.
28Baron, J.; Bourbigot, M.M., "Repair of Escherichia coli and Enterococci in Sea Water After Ultraviolet Disinfection Quantification Using Diffusion Chambers", Journal-Water Res., vol. 30, No. 11, pp. 2817-2821, 1996.
29Blatchley, E.R. III; Bastian, K.C.; Duggirala, R.K.; Alleman, J.E.; Moore, M.; Schuerch, P., "Ultraviolet Irradiation and Chlorination/Dechlorination for Municipal Wastewater Disinfection: Assessment of Performance Limitations," Journal-Water Environ. Res., vol. 68, No. 2, pp. 194-204, 1996.
30Cairns, W.L., "UV Technology for Water Supply Treatment," Journal-Water Supply, vol. 13, No. 3-4, pp. 211-214, 1995.
31Carlson et al, "Project Summary: Ultraviolet Disinfection of Water for Small water Supplies," Office of Research and Development, US Environmental Protection Agency, Cincinnati, OH 1985, EPA/500/52-85/092, prior art.
32Carnimeo, D.; Contini, E.; DiMarino, R.; Donadio, F.; Liberti, L.; Ranieri, E., "Wastewater Disinfection by UV at Trani Municipal Plant," Journal-Water Sci. Technol., vol. 30, No. 4, pp. 125-132, 1994.
33Caufield, J.D., "Specifying and Monitoring Ultraviolet Systems for Effective Disinfection of Water," Journal-AM Fish. Soc. Symp., No. 10, pp. 421-426, 1991.
34Clancy et al, "Ultraviolet Irradiation (UV) for the Inactivation of Cryptosporidium in Water," paper presented at the 1997 AWWA Water Quality Technology Conference (document missing).
35Clancy, Hargy, Marshall, Dykson, "UV Light Inactivation of Cryptosporidium Oocysts," Waterborn Pathogens, vol. 90, Issue 9, Journal AWWA, 1998.
36 *Clancy, J. et al. "UV light inactivation of Cryptosporidium oocysts," Journal of AWWA, vol. 90, No. 9, pp. 92-102, 1998.*
37Darby, J.L.; Snider, K.E.; Tchobanoglous, G., "Ultraviolet Disinfection for Wastewater Reclamation and Reuse Subject to Restrictive Standards," Journal-Water Environ. Res., vol. 65, No. 2, pp. 169-180, 1993.
38David R. Lide, Ph.D., CRC Handbook of Chemistry and Physics, 73rd Edition, 1992-1993.
39De Pue, S.E.; Dudley, R.E., "Water Treatment on the Move, Ultraviolet Disinfecting Works Almost Anywhere," Journal-Water Technol., vol. 17, No. 10, pp. 80-83, 1994.
40Dertiende, Herziene Uitgave, Door Prof. Dr. Guido Geerts En Drs. Ton Den Boon, Van Dale Groot Woordenboek Der Nederlandse Taal, j-r, 1999.
41DVGW Regelwerk, Technische Mitteilung Merkblatt, W 293, UV-Anlagen zur Desinfektion von Trinkwasser, Oct. 1994.
42Eccleston, B., "UV Intensity Levels Affected By Water Quality," Journal-Water Technology, vol. 21, No. 5, pp. 61-68, 1998.
43Excerpts from "Disinfection, Sterilization and Preservation (1991)".
44Farr, B.M.; Gratz, J.C.; Tartaglion, J.C.; Gretchell-White, S.I.; Groeschell, D.H.M., "Evaluation of Ultraviolet Light for Disinfection of Hospital after Contaminated with Legionella," Journal-Lancet, vol. 2, No. 8612, pp. 669-671, 1988.
45 *Furst, G. M.. Abstract of "Advanced ultraviolet irradiation of drinking water inactivates Cryptosporidium and other pathogens," Proc. Ann. Conf. of Americal Water Works Assoc., 1997.*
46Furst, G. Michael, Jr., P.E., Product Manager, Safe Water Solutions LLC, "Advanced Ultraviolet irradiation of Drinking water Inactivates Cryptosporidium and Other Pathogens" American Water Works Association Proceedings, 1997 Annual Conference, Management & Regulations, vol. A (1 of 5) Jun. 15-19, 1997, Atlanta, Georgia.
47Gadgil et al., "Field testing UV Disinfection of drinking Water," Paper presented at the 23rd WEDC Conference "Water Sanitation for All" Sep. 1-5, 1997, Proceedings Published 1997 by the Water Engineering Development Centre, University of Loughborough, UK.
48Gehr, R.; Nicell, J., "Pilot Studies and Assessment of Downstream Effects of UV and Ozone Disinfection of a Physicochemical Wastewater,", Journal-Water Qual. Res. J. Canada, vol. 31, No. 2, pp. 263-281, 1996.
49Gehr, R.; Wright, H., "UV Disinfection of Wastewater Coagulated with Ferric Chloride: Recalcitrance and Fouling Problems," Journal-Water Science & Technology, vol. 38, No. 3, pp. 15-23, 1998.
50Gemne, G.; Hoffner, S.; Stenstroem, T., "Disinfection of Water in a Medical Therapy Pool With Ultraviolet Irradiation," vol. 37, No. 3, pp. 265-274, 1981.
51Gunther O. Schenk, "Ultraviolet Sterilization" Handbook of Water Purification, second edition, Ellis Horwood Series in Water and Wastewater technology, prior art.
52Hancock, George, G.; Davis, Ernst M., "Regrowth Potential of Coliforms after UV Disinfection of Municipal Wastewater," Journal-J Envir Sci Health Pt A, vol. 34, No. 9, pp. 1737-1743, Journal Article, 1999.
53Havelaar, A.H.; Nieuwstad, T.J.; Meulemans, C.C.E.; Van Olphen, M., "F-Specific RNA Bacteriophages as Model Viruses in UV Disinfection of Wastewater," Journal-Water Sci. Technol., vol. 24, No. 2, pp. 347-352, 1991.
54Hengesbach, B.; Schoenen, D.; Hoyen, O; Bernhardt, H.; Mark, G.; Schuchmann, H.P.; von Sonntag, C., "UV Disinfection of Drinking Water-The Question of Bacterial Regrowth and the Photolytic Degradation of Biogenic High-Molecular-Weight Substances," Journal-Aqua, vol. 42, No. 1, pp. 13-22, 1993.
55Hengesbach, B.; Schoenen, D.; Hoyen, O; Bernhardt, H.; Mark, G.; Schuchmann, H.P.; von Sonntag, C., "UV Disinfection of Drinking Water—The Question of Bacterial Regrowth and the Photolytic Degradation of Biogenic High-Molecular-Weight Substances," Journal-Aqua, vol. 42, No. 1, pp. 13-22, 1993.
56Holleman-Wiberg, Lehrbuch der Anorganischen Chemie, 91-100, verbesserte und stark erweirerte Auflage von, Nils Wiberg, WDEG, New York 1985.
57Janex, M.L.; Savoye, P.; Do-Quang, Z.; Blatchley, E.R.III; Laine, J.M., "Impact of Water Quality and Reactor Hydrodynamics on Wastewater Disinfection by UV, Use of CFD Modeling for Performance Optimization," Journal-Water Science & Technology, vol. 38, No. 6, pp. 71-78, 1998.
58Jarol, E.L., "Effect of disinfectants on Giardia cysts," CRC Critical Reviews in Environmental Control, 1988, 18, 1-28.
59Johnson, "Flashblast-the Light that Cleans", Popular Science, pp. 82-84, prior art.
60Johnson, "Flashblast—the Light that Cleans", Popular Science, pp. 82-84, prior art.
61Kolch, Andreas, "Disinfecting Drinking Water with UV Light", Journal-Pollution Engineering, vol. 31, No. 10, pp. 34-36, Oct. 1999.
62Korshin, G., V.; Li, C-W; Benjamin, M.W., "A Theoretical Description of the UV Spectrum of Natural Organic Matter and Changes in UV Absorption During Water Treatment", Journal-Abstracts of Papers American Chemical Society, vol. 210, No. 1-2, 1995, pp. ENVR 133, Meeting Abstract, 210th American Chemical Society National Meeting, Aug. 20-24, 1995, Chicago, Illinois.
63Kusnetsov, J.M.; Keskitalo, P.J.; Ahonene, H.E.; Tulkki, A.I.; Miettinen, I.T.; Martikainen, P.J., "Growth of Legionella and Other Heterotrophic Bacteria in a Circulating Cooling Water System Exposed to Ultraviolet Irradiation", Journal of Applied Bacteriology, vol. 77, No. 4, 1994, pp. 461-466, Research Article.
64LeChevallier, M.W.; Norton, W. D., "Giardia and Ctyptosporidium in Raw and Finished Water" Journal AWWA, Sep. 1995, pp. 5465.
65LeChevallier, M.W.; Norton, W.D.; Lee, R. G., "Occurrence of Giardia and Cryptosporidium spp. In Surface Water Supplies" Journal-Applied and Environmental Microbiology, Sep. 1991, vol. 57, No. 9, pp. 2610-2616.
66Lee, N.E.; Jolley, R.L.; Denton, M.S.; Thompson, J.E., "Ultraviolet Irradiation of Municipal Wastewater: Evaluation of Effects on Organic Constituents," Journal-Environ. Int., vol. 7, No. 6, pp. 403-408, 1982.
67Leveque, F.; Crance, J.M.; Beril, C.; Schwartzbrod, L., "Virucidal Effect of UV Light on Hepatitis A Virus in Sea Water: Evaluation with Cell Culture and RT-PCR," Journal-Water Sci. Technol., vol. 31, No. 5-6, pp. 157-160, 1995.
68Lindenauer, K.G.; Darby, J.L., "Ultraviolet Disinfection of Wastewater: Effect of Dose on Subsequent Photoreactivation," Journal-Water Res., vol. 28, No. 4, pp. 805-817, 1994.
69Liu, Z.; Stout, J.E.; Tedesco, L.; Boldin, M.; Hwang, C.; Yu, V.L., "Efficacy of Ultraviolet Light in Preventing Legionella Colonization of a Hospital Water Distribution System," Journal-Water Res., vol. 29, No. 10, pp. 2275-2280, 1995.
70Loge, et al., Factors Influencing Ultraviolet Disinfection Performance Part I: Light Penetration to Wastewater Particles, Journal-Water Environment Research Ywater Environ Res, vol. 71, No. 3, pp. 377-381, Jun. 1999.
71Loge, et al., Factors Influencing Ultraviolet Disinfection Performance Part II: Light Penetration to Wastewater Particles, Journal-Water Environment Research Water Environ Res, vol. 71, No. 6, pp. 1178-1187, Oct. 1999.
72Loge, F.J.; Emerick, R.W.; Heath, M.; Jacangelo, J.; Tchobanoglous, G.; Darby, J.L., "Ultraviolet Disinfection of Secondary Wastewater Effluents: Prediction of Performance and Design", Journal-Water Environ. Res., vol. 68, No. 5, pp. 900-916, 1996.
73Lund, V.; Hongve, D., "Ultraviolet Irradiated Water Containing Humic Substances Inhibits Bacterial Metabolism," Journal-Water Res., vol. 28, No. 5, pp. 1111-1116, 1994.
74M.E. Ransome, T.N. Whitmore and E.G. Carrington, "Effects of Disinfectants on the Viability of Cryptosporidium parvum Oocysts" Water Supply, vol. 11, Amsterdam, pp. 103-118, 1993, XP002113177.
75M.J. Lorenzo-Lorenzo, M.E. Area-Mazea, I. Villacorta-Martinez de Maturana and Duran-Oreiro, "Effect of Ultraviolet Disinfection of Drinking Water on Viability of Cryptosporidium parvum Oocytes," J. Parasitol, 1993, 79(1), 67-70.
76Moore, N.J.; Margolin, A.B., "Efficacy of Nucleic Acid Probes for Detection of Poliovirus in Water Disinfected by Chlorine, Chlorine Dioxide, Ozone, and UV Radiation," Journal-Appl. Environ. Microbiol., vol. 60, No. 11, pp. 4189-4191, 1994.
77Moreno, B.; Goni, F.; Fernandez, O.; Martinez, J.A.; Astigarraga, M.; Morris, R.; Grabow, W.O.K.; Jofre, J. "The Disinfection of Wastewater by Ultraviolet Light," Journal-Health-Related Water Microbiology 1996; Water Sci. Technol., vol. 35, No. 11-12, pp. 233-235, 1997.
78Nieuwstad, T.J.; Havelaar, A.H.; Van Olphen, M., "Hydraulic and Microbiological Characterization of Reactors for Ultraviolet Disinfection of Secondary Wastewater Effluent," Journal-Water Res., vol. 25, No. 7, pp. 775-783, 1991.
79Nime, F.A.; Burek, J.D.; Page, D.L.; Holscher, M.A.; Yardley, J.H., "Acute Enterocolitis in a Human Being Infected with the Protozoan Cryptosporidium," Journal-Gastroenterology, vol. 70, No. 4, pp. 592-598, 1976.
80Oliver-Daumen, B.; Bach, W.; Kryschi, R., "Die Desinfektion von Wasser in der Brauerei mittels UV-Bestrahlung" [Disinfection of Water in the Brewery by Means of UV Radiation], Journal-Brauwelt, vol. 130, No. 35, pp. 1428-1434, 1990.
81Parrotta, Bekdash, "UV Disinfection of Small Groundwater Supplies", Journal-American Water Works Association Journal, vol. 90, No. 2, 1998, pp. 71-81, ISSN 003-150X.
82Perrot, J.Y.; Baron, J., "The Disinfection of Municipal Wastewater by Ultraviolet Light: A French Case Study", Journal-Water Sci. Technol., vol. 32, No. 7, pp. 167-174, 1995.
83Pulsed-Light Treatment of Food & Packaging, Dunn et al. Food Technology, vol. 49, No. 9, Sep. 1995, pp. 95-98.
84R. LaFrenz, "High Intensity Pulsed UV For Drinking Water Treatment" Proc. AWWA WQT Conference, Denver, CO, Nov. 1997.
85Rajala-Mustonen, R.L.; Toivola, P.S.; Heinonen-Tanski, H.; Morris, R.; Grabow, W.O.K., "Effects of Peracetic Acid and UV Irradiation on the Inactivation of Coliphages in Wastewater," Journal-Health-Related Water Microbiology 1996; Water Sci. Technol., vol. 35, No. 11-12, pp. 237-241, 1997.
86Rentschler, et al., "Bactericidal Effect of Ultraviolet Radiation", Research Department, Westinghouse Lamp Division, Bloomfield, New Jersey, pp. 745-774, 1940.
87Rice E. W; Hoff J.C: "Inactivation of Giardia Lamblia by Ultraviolet Irradiation" Applied and Environmental Microbiology, vol. 42, No. 3, Sep. 1981 (1981-09), pp. 546-547 XP000949317.
88Rijal, G; Fujioka, R., "Evaluation of UV Disinfection System in the Inactivation of Various Indicator Organisms in Wastewater Effluents", Journal-Abstracts of the General Meeting of the American Society for Microbiology, vol. 94, 1994, pp. 388, Meeting Abstract, 94th General Meeting of the American Society for Microbiology, May 23, 27, 1994, Las Vegas, Nevada.
89Rodriquez, J.; Gagnon, S., "UV Provides Rx for Medical Water," Journal-Water Technol, vol. 19, No. 4, pp. 34-42, 1996.
90Rose, J.B., "Survey of Potable Water Supplies for Cryptosporidium and Giardia," Journal-Environ. Sci. Technol., vol. 25, No. 8, 1991, pp. 1383-1400.
91Rose, J.B., Occurrence and Significance of Cryptosporidium in Water, Journal AWWA, Research & Technology, Feb. 1988, pp. 53-58.
92Sobotka, J., "The Efficiency of Water Treatment and Disinfection by Means of Ultraviolet Radiation," Journal-Water Sci. Technol., vol. 27, No. 3-4, pp. 343-346, 1993.
93Sobotka, M, et al., "Application for Ultraviolet Radiation for Water Disinfection and Purification in Poland," Journal-Water Sci. Technol., vol. 26, No. 1-12, pp. 2313-2316, 1992.
94Sommer, R.; Cabaj, A., "Evaluation of the Efficiency of a UV Plant for Drinking Water Disinfection," Journal-Water Sci. Technol., vol. 27, No. 3-4, pp. 357-362, 1993.
95Sommer, R.; Cabaj, A.; Haider, T., "Microbicidal Effect of Reflected UV Radiation in Devices for Water Disinfection," Journal-Water Sci. Technol., vol. 34, No. 7-8, pp. 173-171, 1996.
96Sommer, R.; Cabaj, A.; Pribil, W.; Haider, T.; Morris, R.; Grabow, W.O.K.; Jofre, J., "Influence of Lamp Intensity and Water Transmittance on the UV Disinfection of Water," Journal-Health-Related Water Microbiology 1996; Water Sci. Technol., vol. 35, No. 11-12, pp. 113-118, 1997.
97Sommer, R.; Haider, T.; Cabaj, A.; Pribil, W.; Lhotsky, M., "Time Dose Reciprocity in UV Disinfection of Water," Journal-Water Science & Technology, vol. 38, No. 12, pp. 145-150, 1998.
98Sundstrom, D. W.; Weir, B.A.; Barber, T.A.; Klei, H.E.; "Destruction of Pollutants and Microorganisms in Water by UV Light and Hydrogen Peroxide," Journal-Water Pollut Res J Can, vol. 27, No. 1, pp. 57-68, 1992.
99Tree, J.A.; Adams, M.R.; Lees, D.N.; Morris, R.; Grabow, W.O.K.; Jofre, J., "Virus Inactivation During Disinfection of Wastewater by Chlorination and UV Irradiation and the Efficacy of F uper(+) Bacteriophage as a "Viral Indicator"" , Journal-Health-Related Water Microbiology 1996; Water Sci. Technol., vol. 35, No. 11-12, pp. 227-232, 1997.
100Tyzzer, E.E., "A Sporozoan Found in the Peptic Glands of the Common Mouse," Article from the Laborary of the Caroline Brewer Croft Fund Cancer Commission of Harvard University, prior art.
101Water Supply, vol. 11, Amsterdam, pp. 103-118, 1993 entitled: "Effects of Disinfectants on the Viability of Cryptosporidium Parvum Oocysts" Authors: M.E. Ransome, T.N. Whitmore and E.G. Carrington.
102Whitby, G.E.; Palmateer, G., "Effect of UV Transmission, Suspended Solids and Photoreactivation on Microorganisms in Wastewater Treated with UV Light," Journal-Water Sci Technol, vol. 27, No. 34- pp. 379-386, 1993.
103Wiedenmann, A. Fischeter, B; Straub, U.; Wang, C.-H.; Flehmig, B; Schoenen, D., "Disinfection of Hepatitis A Virus and MS-2 Coliphage in Water by Ultraviolet Irradiation: Comparison of UV-Susceptibility," Journal-Water Sci. Technol., vol. 27, No. 3-4, p. 335-338, 1993.
104Wolfe, "Ultraviolet disinfection of potable water," Environmental Science and Technology, Vo. 24, pp. 768-772 (1990).
105Zemke, V.; Podgorsek, L.; Schoenen, D., Ultraviolet Disinfection of Drinking Water. 1. Communication: Inactivation of E. coli and Coliform Bacteria, Journal-Zentralbl. Hyg. Mweltmed., vol. 190, No. 1-2, pp. 51-61, 1990.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6982039Feb 19, 2004Jan 3, 2006The United States Of America As Represented By The Secretary Of The ArmyMethod for improving ultraviolet radiation disinfection of water using aqueous silver
US7038219 *Oct 26, 2001May 2, 2006Purepulse Technologies, Inc.Sterilization of packages and their contents using light
US7217933Dec 12, 2005May 15, 2007Waterhealth International, Inc.UV water disinfector
US7422695Sep 7, 2004Sep 9, 2008Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US7494502Jul 21, 2005Feb 24, 2009Keraderm, LlcAlteration of the skin and nail for the prevention and treatment of skin and nail infections
US7553456Apr 27, 2006Jun 30, 2009Sensor Electronic Technology, Inc.Organism growth suppression using ultraviolet radiation
US7578937Jul 2, 2008Aug 25, 2009Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US7622693Jul 15, 2002Nov 24, 2009Foret Plasma Labs, LlcPlasma whirl reactor apparatus and methods of use
US7634996Feb 13, 2007Dec 22, 2009Sensor Electronic Technology, Inc.Ultraviolet radiation sterilization
US7857972Apr 5, 2007Dec 28, 2010Foret Plasma Labs, LlcApparatus for treating liquids with wave energy from an electrical arc
US7862728Sep 27, 2007Jan 4, 2011Water Of Life, Llc.Ultraviolet water purification system
US7870822Jan 19, 2006Jan 18, 2011Ecolab Usa Inc.Method and system for recapturing and reusing unreacted antimicrobial solutions in spray applications
US7897053Jul 20, 2009Mar 1, 2011Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US7985342Jul 20, 2009Jul 26, 2011Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US8088290Jul 2, 2008Jan 3, 2012Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US8110100Nov 18, 2010Feb 7, 2012Foret Plasma Labs, LlcSystem for treating liquids with wave energy from an electrical arc
US8157761Jul 5, 2007Apr 17, 2012Baxter International Inc.Peritoneal dialysis patient connection system
US8324523Oct 9, 2009Dec 4, 2012Foret Plasma Labs, LlcPlasma whirl reactor apparatus and methods of use
US8329044Nov 29, 2011Dec 11, 2012Foret Plasma Labs, LlcMethod of treating fluids contaminated with anthrax or legionella using wave energy from a carbon arc
US8337709Dec 27, 2011Dec 25, 2012Foret Plasma Labs, LlcMethod for treating liquids with wave energy from an electrical arc
US8343342Dec 27, 2011Jan 1, 2013Foret Plasma Labs, LlcApparatus for treating liquids with wave energy from an electrical arc
US8357873Oct 10, 2009Jan 22, 2013Foret Plasma Labs, LlcPlasma whirl reactor apparatus and methods of use
US8366925Nov 29, 2011Feb 5, 2013Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US8506886Jun 20, 2008Aug 13, 2013Uvcleaning Systems, Inc.Ultraviolet photoreactor for the purification of fluids
US8529770Oct 8, 2009Sep 10, 2013Water Of Life, Llc.Self-contained UV-C purification system
US8597523Nov 27, 2012Dec 3, 2013Foret Plasma Labs, LlcMethod for treating liquids with wave energy from an electrical arc
US8603333Feb 4, 2013Dec 10, 2013Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US8613856Feb 4, 2013Dec 24, 2013Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US8628660Feb 4, 2013Jan 14, 2014Foret Plasma Labs, LlcTreatment of fluids with wave energy from a carbon arc
US8641898Nov 28, 2012Feb 4, 2014Foret Plasma Labs, LlcApparatus for treating liquids with wave energy from an electrical arc
US20100147780 *Aug 1, 2007Jun 17, 2010Japan Health Sciences FoundationFilter for filtration and recovery of suspended particles in water, and method for filtration and recovery of suspended particles in water and method for water quality management using the filter
Classifications
U.S. Classification210/748.11, 422/23
International ClassificationA61L2/10, C02F1/32
Cooperative ClassificationC02F1/32, C02F2201/326, A61L2/10, C02F2303/04
European ClassificationA61L2/10, C02F1/32
Legal Events
DateCodeEventDescription
Nov 22, 2010FPAYFee payment
Year of fee payment: 8
Jan 26, 2009ASAssignment
Owner name: BERSON MILIEUTECHNIEK BV, NETHERLANDS
Free format text: LICENSE;ASSIGNOR:CALGON CARBON CORPORATION;REEL/FRAME:022151/0209
Effective date: 20090123
Dec 4, 2007RFReissue application filed
Effective date: 20070905
Nov 8, 2006FPAYFee payment
Year of fee payment: 4
Apr 27, 1999ASAssignment
Owner name: CALGON CARBON CORPORATION, PENNSYLVANIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BOLTON, JAMES R.;STEVENS, R.D. SAMUEL;DUSSERT, BERTRAND;REEL/FRAME:009932/0110
Effective date: 19990423